I think you just MAY be asking too much from your device - especially with simply smearing grease on it and then running it continuously at 1600rpm and surely under oscillatory operation which surely can't be helped eventuall.
The key give away is the "smoking".
The smoke point of grease is essentially at or above the failing point of the lubricant. The purpose of grease is to lube but, in some respects, also to hellp transfer some heat between the rubbing members. When the grease is smoking, it is literally telling you that it is getting too hot to lube anymore - the grease has turned from grease to watery slime and lubrication is probably less than even marginal.
I doubt seriously that one could/should expect all thread rod to transmit power at 1600 rpm continuously - especially without continous lube replenishment.
Moeover, it is one thing to oscillate back and forth rationally and then encounter a siezure - it is another thing to take fastern rod, mis-use it to transmit power and then do it under boundary/marginal lube conditions, ESPECIALLY at 1000+ rpm at a continuous duty cycle and be surprised when/if it fails.
Even a ground ball screw, oontinuously operated at that speed and under oscillation without lube replenishment would run into problems!!!
If however, this is how your plan to run your machine, I seriously suggest then that you figure out a way to better and continously replenish the lube on whatever screw you use on the axis. The way you're doing it seems to be a bit too harsh for your selected lubrication regime.  |